U.S. Magistrate Judge Patrick Hunt agreed to let Raoul Weil stay with friends in New Jersey after putting up the bond, which included $9 million in a personal surety by Weil, $500,000 from the New Jersey family and the other $1 million a corporate surety bond signed with a bail bondsman.

Weil, the ex-head of wealth management at UBS, was arrested in mid-October on vacation with his wife at an upscale hotel in the northern Italian city of Bologna. He is charged with helping Americans dodge taxes via secret Swiss bank accounts.

If convicted, Weil faces up to five years in prison for conspiracy to commit tax fraud.

The judge ordered Weil be placed on a GPS monitoring system and surrender his passport.

Weil's attorney told the court that his client had assets of $11.2 million, all held offshore, mostly in cash and securities.

His trial could help the United States and other Western countries step up their hunt for individuals and companies that use opaque offshore financial centres to avoid paying taxes.

Five years ago the United States charged Weil and other unnamed executives from UBS with helping more than 17,000 Americans conceal $20 billion in secret Swiss bank accounts. Weil disputed the charges and was declared a fugitive a few months later.

He left UBS after being indicted, and joined a small Swiss bank, Reuss Private Group.

In a landmark 2009 settlement UBS paid a $780 million fine and agreed to hand over the names of U.S. clients with secret accounts, breaking Switzerland's tradition of banking secrecy, to avoid feared criminal charges against the bank or other executives.